Monoclonal antibodies ( mAbs ) of African cassava mosaic virus ( ACMV ) and ELISA technique were used to investigate the presence of geminiviruses in plants showing geminiviruses-like symptoms in different regions in Saudi Arabia. TYLCV was detected, for the first time in the Kingdom, in samples of tomato plants collected from different locations. Three other geminiviruses were also detected in the following plant species : Hibiscus esculentus L. , Medicago sativa L. , and Cucurbita pepo L. These viruses reacted with at least one of four mAbs of ACMV. The test was negative to samples collected from Vigna unguiculata L. Walp. Subsp., Capsicum annum L. , Citrullus lanatus L. , Vinca rosa L. and Chenopodium spp. TYLCV was found to be of wider spread than the other detected geminiviruses which seem to be confined to the southern part of the country.